c# - 我在连接 SQL Server 时遇到异常

Question

    private void frmResibo_Load(object sender, EventArgs e)
    {

        market m = new market();
        string cs = @"Data Source =.localhost; Initial Catalog = thesisdb; User ID=root; Integrated Security = true";
        SqlConnection cn = new SqlConnection(cs);
        SqlDataAdapter da = new SqlDataAdapter("select * from tbl_itemlist", cn);
        da.Fill(m, m.Tables[0].TableName);



         ReportDataSource rds = new ReportDataSource("tbl_itemlist", m.Tables[0]);
         this.reportViewer1.LocalReport.DataSources.Clear();
         this.reportViewer1.LocalReport.DataSources.Add(rds);
         this.reportViewer1.LocalReport.Refresh();

         this.reportViewer1.RefreshReport();

    }

我在“da.Fill---”行中遇到了这样的错误

System.Data.SqlClient.SqlException: 'A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)'

Answer 1

连接字符串指定“Data Source =.localhost”；通常您可以输入“Data Source = .”或“Data Source = localhost”(两者含义相同:运行它的计算机)。但是，由于 localhost 前面有一个点，它可能会尝试查找名为“.localhost”的计算机，这可以解释为什么它无法连接到该 SQL 服务器。

另请注意，您的 SQL 连接和数据适配器是一次性的，因此应位于“using” block 中。